Eleven-year olds definitely have their own opinions about diet, exercise and weight-loss; and it is mostly their opinions — not those of their parents — that affect their lifestyle changes. Nevertheless, while parents’ opinions are secondary, they still count for something, a new study suggests.

Preteens who believed they needed to lose weight or believed their thought so were more likely to plan to do so, found the study appearing online in the journal Health Promotion Practice. Children who ate healthy made that choice based in part their parents’ influence or because their parents planned to lose weight — but that influence had already started to wane by age 11, the study found.

Led by Lesley Cottrell, Ph.D., section chief for epidemiological research at West Virginia University, researchers asked 342 children and their parents about the children’s intention to lose weight, eat healthier and exercise more. The goal was to find who or what motivates children to change their lifestyles — information that would contribute to developing effective medical programs in this area.

As the main guardians of their children, parents play an important role in choosing food items and encouraging . Cottrell said the interplay between parents’ influence on their children’s health decisions is complex but likely to decrease as the child develops. In this study, for instance, 11-year olds probably are applying eating habits that evolved from their parents’ influence in earlier years.

“Children do have a role in these decisions,” Cottrell said, “so we cannot focus programs on just the parent or just the child.” She said the study will help health care providers decide whether to include children when discussing healthy lifestyles for the family and, if so, at what age and what their roles should be.

Richard Boles, Ph.D., of the Children’s Eating Laboratory at the University of Colorado Denver, said the study supports the importance of taking a family-based approach. That parents greatly underestimate the child’s obesity is an important point in how plan behavior, he said. Thus, parents who are concerned about their child’s obesity might make it easier for the child to develop good intentions about health.

More information: Cottrell L. Identifying the influential people and factors that influence children’s intention to make lifestyle changes. Health Promotion Practice online, 2010.